Poor h2o GBM Classification Performance in a balanced binomial response - h2o

Question

In a fairly balanced binomial classification response problem, I am observing unusual level of error in h2o.gbm classification for determining class 0, on train set itself. It is from a competition which is over, so interest is only towards understanding what is going wrong.
Confusion Matrix (vertical: actual; across: predicted) for F1-optimal threshold:
0 1 Error Rate
0 147857 234035 0.612830 =234035/381892
1 44782 271661 0.141517 =44782/316443
Totals 192639 505696 0.399260 =278817/698335
Any expert suggestions to treat the data and reduce the error is welcome.
Following approaches are tried and error is not found decreasing.
Approach 1: Selecting top 5 important variables via h2o.varimp(gbm)
Approach 2: Converting the negative normalized variable as zero and possitive as 1.
#Data Definition
# Variable Definition
#Independent Variables
# ID Unique ID for each observation
# Timestamp Unique value representing one day
# Stock_ID Unique ID representing one stock
# Volume Normalized values of volume traded of given stock ID on that timestamp
# Three_Day_Moving_Average Normalized values of three days moving average of Closing price for given stock ID (Including Current day)
# Five_Day_Moving_Average Normalized values of five days moving average of Closing price for given stock ID (Including Current day)
# Ten_Day_Moving_Average Normalized values of ten days moving average of Closing price for given stock ID (Including Current day)
# Twenty_Day_Moving_Average Normalized values of twenty days moving average of Closing price for given stock ID (Including Current day)
# True_Range Normalized values of true range for given stock ID
# Average_True_Range Normalized values of average true range for given stock ID
# Positive_Directional_Movement Normalized values of positive directional movement for given stock ID
# Negative_Directional_Movement Normalized values of negative directional movement for given stock ID
#Dependent Response Variable
# Outcome Binary outcome variable representing whether price for one particular stock at the tomorrow’s market close is higher(1) or lower(0) compared to the price at today’s market close
temp <- tempfile()
download.file('https://github.com/meethariprasad/trikaal/raw/master/Competetions/AnalyticsVidhya/Stock_Closure/test_6lvBXoI.zip',temp)
test <- read.csv(unz(temp, "test.csv"))
unlink(temp)
temp <- tempfile()
download.file('https://github.com/meethariprasad/trikaal/raw/master/Competetions/AnalyticsVidhya/Stock_Closure/train_xup5Mf8.zip',temp)
#Please wait for 60 Mb file to load.
train <- read.csv(unz(temp, "train.csv"))
unlink(temp)
summary(train)
#We don't want the ID
train<-train[,2:ncol(train)]
# Preserving Test ID if needed
ID<-test$ID
#Remove ID from test
test<-test[,2:ncol(test)]
#Create Empty Response SalePrice
test$Outcome<-NA
#Original
combi.imp<-rbind(train,test)
rm(train,test)
summary(combi.imp)
#Creating Factor Variable
combi.imp$Outcome<-as.factor(combi.imp$Outcome)
combi.imp$Stock_ID<-as.factor(combi.imp$Stock_ID)
combi.imp$timestamp<-as.factor(combi.imp$timestamp)
summary(combi.imp)
#Brute Force NA treatment by taking only complete cases without NA.
train.complete<-combi.imp[1:702739,]
train.complete<-train.complete[complete.cases(train.complete),]
test.complete<-combi.imp[702740:804685,]
library(h2o)
y<-c("Outcome")
features=names(train.complete)[!names(train.complete) %in% c("Outcome")]
h2o.shutdown(prompt=F)
#Adjust memory size based on your system.
h2o.init(nthreads = -1,max_mem_size = "5g")
train.hex<-as.h2o(train.complete)
test.hex<-as.h2o(test.complete[,features])
#Models
gbmF_model_1 = h2o.gbm( x=features,
y = y,
training_frame =train.hex,
seed=1234
)
h2o.performance(gbmF_model_1)

Answer 1

You've only trained a single GBM with the default parameters, so it doesn't look like you've put enough effort into tuning your model. I'd recommend a random grid search on GBM using the h2o.grid() function. Here is an H2O R code example you can follow.